US3829366A - Treatment of titanium cathode surfaces - Google Patents

Treatment of titanium cathode surfaces Download PDF

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Publication number
US3829366A
US3829366A US00301339A US30133972A US3829366A US 3829366 A US3829366 A US 3829366A US 00301339 A US00301339 A US 00301339A US 30133972 A US30133972 A US 30133972A US 3829366 A US3829366 A US 3829366A
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United States
Prior art keywords
titanium
cathode
aqueous solution
copper
film
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Expired - Lifetime
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US00301339A
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English (en)
Inventor
A Ives
J Atkinson
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Imperial Metal Industries Kynoch Ltd
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Imperial Metal Industries Kynoch Ltd
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C1/00—Electrolytic production, recovery or refining of metals by electrolysis of solutions
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/60—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using alkaline aqueous solutions with pH greater than 8
    • C23C22/64—Treatment of refractory metals or alloys based thereon

Definitions

  • an electrolyte containing ions of the metal to be refined is brought into contact with an anode and a cathode, a current is passed between the two electrodes and the metal is deposited on the cathode.
  • the anode may be formed from the metal being refined, in which case it goes into solution at the same rate as the rate of deposition onto the cathode.
  • it may be formed from a passive material, and the deposition then being accompanied by a depletion of the metal ions from the solution.
  • the cathode can either be made from the metal which is being deposited or from some other metal.
  • the cathode can be a simple titanium sheet on which the copper is deposited.
  • the copper may be thinly plated to form a thin sheet, which is subsequently removed and used as a starter blank.
  • the copper may be thickly deposited and then stripped off in slab form.
  • the deposition of the copper onto the titanium sheet must be uniform and the copper must be readily removable once deposition is complete.
  • a method of extracting a metal from an electrolyte which comprises contacting the lectrolyte with an anode and a cathode, and passing an electric current between the anode and the cathode, wherein the cathode has a surface of titanium or a titanium alloy, the surfacehaving been treated by insertion into a substantially fluoride-free alkaline aqueous solution and an organic complexing agent for titanium selected from the group: an ether, an alcohol, an aldehyde, a ketone, an amine, a nitrile, a sugar, a salt of an organic acid or any of their derivatives, the arrangement being such that a continuously thickening distorted anatase titanium oxide film is formed on the titanium or titanium alloy surface.
  • the complex formed by the complexing agent may be unstable in water.
  • the solution may be at ambient temperature or at an elevated temperature.
  • the organic complexing agent may be chosen from the group sodium gluconate, triethanolamine or ethylene diamino tetra acetic acid.
  • the solution may be chosen from (a) 25 wt. percent sodium hydroxide, 1-7 wt. percent sodium gluconate aqueous solution, or
  • the oxide may be built up until it attains a black appearance corresponding to a minimum thickness of 750 A. to 3000 A.
  • the alkali may be an alkaline metal hydroxide.
  • the surface of titanium or titanium alloy may be connected as an anode and a voltage may be passed through the anode during its insertion in the substantially fluoride free alkaline aqueous solution of the organic complexing agent for titanium.
  • the anode voltage may be less than 12 v. and may be approximately 6 v.
  • the solution may contain an alkaline metal hydroxide or ammonium hydroxide.
  • the complex formed by the organic complexing agent may be unstable in water and the solution may be at ambient temperature or at an elevated temperature.
  • the complexing agent and solutions may be chosen from the groups mentioned above.
  • the present invention also provides a cathode for an electrolytic cell, the cathode having a surface of titanium or a titanium alloy, the surface having been treated by insertion into a substantially fluoride-free alkaline aqueous solution including an organic complexing agent for titanium selected from the group consisting of an ether, an alcohol, an aldehyde, a ketone, an amine, a nitrile, a sugar, a salt of an organic acid or any of their derivatives, so that a thickened distorted anatase titanium oxide film has been formed on the titanium or titanium alloy surface.
  • an organic complexing agent for titanium selected from the group consisting of an ether, an alcohol, an aldehyde, a ketone, an amine, a nitrile, a sugar, a salt of an organic acid or any of their derivatives, so that a thickened distorted anatase titanium oxide film has been formed on the titanium or titanium alloy surface.
  • the complex formed by the complexing agent may be unstable in water and the solution may be at ambient or at an elevated temperature.
  • the organic complexing agents may be chosen from those detailed above as may the solutions.
  • the surface of the cathode may be connected as an anode and a voltage passed through the anode during its insertion in the substantially fluoride free alkaline aqueous solution of the organic complexing agent for titanium.
  • the anode voltage may be less than 12 v. and may be approximately 6 v.
  • the present invention further provides for the use of surface of titanium or a titanium alloy as a cathode in electrolytic metal extraction from an electrolyte characterised in that the surface has a thickened distorted anatase titanium oxide film on the surface produced by immersion of the surface in a substantially fluoride-free alkaline aqueous solution and an organic complexing agent for titanium selected from the group: an ether, an alcohol, an aldehyde, a ketone, an amine, a nitrile, a sugar, a salt of an organic acid, or any of their derivatives.
  • the complex formed by the complexing agent may be unstable in water and the solution may be at ambient or an elevated temperature.
  • the organic complexingagen't may be chosen from those detailed above as may the solution.
  • the surface of titanium or titanium alloy may be connected as an anode and a voltage passed through the anode during its insertion in a substantially fluoride free alkaline aqueous solution of the organic complexing agent for titanium.
  • the anode voltage may be less than 12 v. and may be approximately 6 v.
  • the electrolytic cell comprises a bath 1 of concrete with a polyethylene liner 2, an electrolyte 3 in the bath contains an anode 4 and a cathode 5.
  • the anode 4 is a copper anode and the electrolyte is a 20 wt. percent copper sulphate 10 wt. percent sulphuric acid aqueous solution.
  • the cathode 5 is a sheet of commercial purity titanium plate (designated IMI 130) which has been treated as follows:
  • a 25 wt. percent NaOH, 7 wt. percent sodium gluconate aqueous solution was prepared, heated to 60 C., and the piece of titanium was inserted and connected as an anode.
  • a potential of 6 v. was established between the anode and a cathode.
  • a film of oxide built up gradually and continuously. In the space of one hour, the film grew to an approximate thickness of 2000 A. and had a black appearance. This is in complete contrast to the expected result which would have been that the film would build up, and then as its resistance increases the rate of build up would be expected to slow rapidly until the thickness reaches a peak thickness dependent on the voltage.
  • the tables show that the growth of a suitable film is time, temperature and voltage dependent.
  • the voltage applied has an upper limit dependent on the solution, but the upper limit tends to be the potential at which gas evolution occurs.
  • the gas tends to agitate the solution.
  • the mechanism of deposition of the film may be that the titanium on the plate is taken into solution in the form of a titanium complex which is basically unstable. Decomposition of the unstable complex releases titanium ions which are deposited on the surface. The disruptive effect of the gas bubbles interferes with the complexing and deposition arrangement and thus stops the growth of the film. It is found that voltages of 30 v. are normally disruptive.
  • the reason for a titanium cathode with the film produced by the invention being so suitable is not completely clear. Without prejudice to the invention, it is believed that the thick film of the invention fills in mechanical defects on the surface, and hence reduces the mechanical keying effect of the copper or other metal eventually plated onto the surface. In addition, the more uniform surface of the invention produces a large number of nucleation sites of approximately equal, low free energy of formation. These many nucleation sites result in a small amount of sideways growth from the sites, and consequently an even growth with no'pinholes in the copper. Thus the surface of the invention is both easy to grow on because of the large number of nucleation sites,
  • the black colour of the film is formed after passing through brown, dark green, red and dark blue.
  • the character of the film is the same, only the thickness has changed.
  • the cathode may be formed by mere immersion of the titanium into the NaOH/ sodium gluconate bath without anodisation, although the time needed is seven days. Again a black film built up on the surface, and its structure was proved to be a distorted anatase by X-ray crystallography.
  • a cathode of the coated titanium was then inserted into the cell. It was found that a very even coating of copper formed on the cathode, and that this copper coating stripped readily to form a sheet of copper suitable for a starter sheet.
  • the titanium mother plate was substantially unaffected and was immediately suitable for re-use.
  • Such a titanium mother plate can be usefully substituted for the copper mother plates which have been in common use hitherto.
  • a supply of thin sheets of copper known as starter sheets
  • starter sheets which forms the cathodes onto which the copper is deposited.
  • Electrolytic refiners can make their own copper starter sheets most cheaply by depositing electrolytically a layer of copper onto a plate and then stripping the plate after a certain thickness has built up.
  • a release agent is used to' enable the copper starter sheets to be stripped from the mother plates. This release agent tends to contaminate the main electrolyte as it tends to be carried into the main electrolyte on the starter sheet.
  • a surface coating produced according to the invention may be used on a drum or a continuous belt of titanium which acts as a cathode and which is passed through an electrolyte to have a suitable metal such as copper, nickel, or silver continuously electroplated onto the surface and continuously stripped ofl? to form a continuous strip of relatively thin metal.
  • a suitable metal such as copper, nickel, or silver continuously electroplated onto the surface and continuously stripped ofl? to form a continuous strip of relatively thin metal.
  • the cathodes are also particularly suitable for .cathode starters in gold electrolytic recovery, where :they can be substituted for the gold starter sheets used before, with a. great saving in the amount of capital tied up in the sheet.
  • a method of extracting a. metal from an aqueous solution of a salt of the metal by electrolytic depos1t1on of the metal onto a cathode surface of a treated titanium surface of titanium or a titanium alloy inserting the surface into a substantially [fluoride-free alkaline aqueous solution of' an organic complexing agentior titanium selected from the group consisting of an ether, an alcohol, an aldehyde, a ketone, an amine, a nitrile, a sugar, a salt of an organic acid and derivatives thereof, so that a continuously thickening distorted anatase titanium oxide film is formed on the titanium or titanium alloy surface, removing the surface from the solution, and at least once thereafter inserting the treated surface into the aqueous solution of the metal, connecting the treated surface as a cathode, electrodepositing the metal onto the surface and removing the electrodeposited metal from the surface.
  • organic complexing agent is chosen from the group consisting of sodium glucouate, triethanolamine, and ethylene diamino tetra acetic acid.
  • a method as claimed in claim 1 in which the surface of titanium or a titanium alloy is connected as an anode, and a voltage is passed through the anode during its insertion in the substantially fluoride-free alkaline aqueous solution of the organic complexing agent for titanium.

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  • Chemical & Material Sciences (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Electrochemistry (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
US00301339A 1971-11-05 1972-10-27 Treatment of titanium cathode surfaces Expired - Lifetime US3829366A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB5149071 1971-11-05
GB5148971A GB1407208A (en) 1971-11-05 1971-11-05 Treatment of titanium

Publications (1)

Publication Number Publication Date
US3829366A true US3829366A (en) 1974-08-13

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US00301339A Expired - Lifetime US3829366A (en) 1971-11-05 1972-10-27 Treatment of titanium cathode surfaces

Country Status (8)

Country Link
US (1) US3829366A (fr)
AU (1) AU472168B2 (fr)
BE (1) BE790811A (fr)
CA (1) CA1020490A (fr)
DE (1) DE2253912A1 (fr)
ES (1) ES408257A1 (fr)
GB (1) GB1407208A (fr)
ZM (1) ZM17172A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4040914A (en) * 1976-04-28 1977-08-09 Diamond Shamrock Technologies S.A. Cathode starting blanks for metal deposition
US4129492A (en) * 1975-12-23 1978-12-12 Imperial Metal Industries (Kynoch) Limited Electrolytic cell
US4620897A (en) * 1983-09-19 1986-11-04 Fujitsu Limited Method for growing multicomponent compound semiconductor crystals
US5074972A (en) * 1983-12-01 1991-12-24 Mbb Gmbh Surface treatment of ti or ti alloy parts for enhancing adhesion to organic material
US20030137304A1 (en) * 2002-01-22 2003-07-24 Danylyk Donald Bohdan E-water machine
CN103014813A (zh) * 2012-11-23 2013-04-03 北京星航机电设备厂 一种绿色系钛合金微弧氧化着色溶液及其制备方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3427543A1 (de) * 1983-12-01 1985-07-04 Messerschmitt-Bölkow-Blohm GmbH, 2800 Bremen Verfahren zur oberflaechenbehandlung von werkstuecken aus titan

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4129492A (en) * 1975-12-23 1978-12-12 Imperial Metal Industries (Kynoch) Limited Electrolytic cell
US4040914A (en) * 1976-04-28 1977-08-09 Diamond Shamrock Technologies S.A. Cathode starting blanks for metal deposition
US4620897A (en) * 1983-09-19 1986-11-04 Fujitsu Limited Method for growing multicomponent compound semiconductor crystals
US5074972A (en) * 1983-12-01 1991-12-24 Mbb Gmbh Surface treatment of ti or ti alloy parts for enhancing adhesion to organic material
US20030137304A1 (en) * 2002-01-22 2003-07-24 Danylyk Donald Bohdan E-water machine
US6673217B2 (en) * 2002-01-22 2004-01-06 Donald Bohdan Danylyk E-water machine
CN103014813A (zh) * 2012-11-23 2013-04-03 北京星航机电设备厂 一种绿色系钛合金微弧氧化着色溶液及其制备方法

Also Published As

Publication number Publication date
GB1407208A (en) 1975-09-24
BE790811A (fr) 1973-04-30
ZM17172A1 (en) 1973-06-21
AU4845272A (en) 1974-05-02
AU472168B2 (en) 1976-05-20
DE2253912A1 (de) 1973-06-20
ES408257A1 (es) 1976-02-16
CA1020490A (en) 1977-11-08

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